Spring system for vibratory parts feeders



Aug. 5; 1969- Filed May 22, 1967 M- J. PIROUTEK SPRING SYSTEM FOR VIBRATORY PARTS FEEDERS 2 Sheets-Sheet 1 m I I I HI: 3;

INYENTOR. J4 Mares/av J pzroazek f BY Aug. 5, 1969 M. J. PIROUTEK 3,459,292

I SPRING SYSTEM FOR VIBRATORY PARTS FEEDERS- Filed May 22, 1967 2 Sheets-Sheet 2 INVENTOR. M: rosZa v J. Pzroutek l i 'l BY United States Patent US. Cl. 198-220 14 Claims ABSTRACT OF THE DISCLOSURE The disclosed spring system for vibratory feeders includes plural spring mounting units, each consisting of an inclined stack of leaf springs affixed at its lower end to a base and rigidly connected at its upper end to the lower portion of a spring plate. The upper portion of the spring plate is fixedly connected to a feeder bowl. In the preferred embodiment, L-shaped adaptor blocks are connected to each end of the leaf spring stack and are themselves respectively connected to the base and the spring plate at points on a common center line, thereby facilitating alteration of the angular orientation of each leaf spring stack.

BACKGROUND OF THE INVENTION Typically, prior art vibratory feeders and conveyors of the type to which my invention is applicable employ spring mounting units each consisting of a leaf spring, or a plurality of such springs stacked together, fixedly connected at one end to the massive base and at the other end ultimately to the feeder bowl. Each leaf spring or leaf spring stack is typically inclined at an angle of from 15 to 30 off vertical while supporting a plate on which the feeder bowl is mounted. The feeder bowl is vibrated by a vibratory motor such as an electromagnetic motor consisting of a field core fixed to the massive base and surrounded by a coil winding. An armature is fixed to the bottom of the mounting plate at a location spaced from the pole face or faces of the field core by an air gap. Electrical energization of the coil winding attracts the armature pulling the feeder bowl downward. Due to the angular orientation of the leaf springs, there is a horizontal component of movement of the feeder bowl as well as a vertical component. When the coil winding is energized with discrete current pulses, the feeder bowl is returned to its normal position by the leaf springs in the interval between current pulses. This repetitive or vibratory movement of the feeder bowl causes objects therein to propagate.

The feeder bowl, as the name implies, is bowl-shaped and has a helical, inclined path or ramp running along its inner sidewall. The objects in the bowl are induced by the vibratory movement of the feeder bowl to move up the ramp in single file. The objects feed from the termination of the ramp at the rim of the feeder bowl one-by-one for automated processing or assembly with other objects.

Since in vibratory feeders of this type the spring units are spaced circumferentially about and beneath the feeder bowl, the horizontal component of movement of the feeder bowl is actually along an arcuate path; the feeder bowl being incrementally rotated about its vertical axis. Consequently, the leaf springs are subjected not only to a downward force resulting in flexure transverse to their longitudinal axes, but also a torsional force causing them to twist about their longitudinal axes. As a result, the leaf springs operate with less than normal flexibility, and the bolts or the like securing the ends of the leaf springs are subjected to significant stresses.

I have found that by connecting one of the ends of the leaf spring or leaf spring stack of each spring mounting unit to either the feeder bowl or the base through an additional spring member, the motional response to the vibratory motor is enhanced. This is due to the fact that the additional spring members absorb the torsional forces and the leaf springs are not forced to twist. Consequently, for a given energization level of the vibratory motor, the amplitude of feeder bowl movement is greater with the additional spring member than without. Increased efficiency is therefore obtained. Being permitted increased flexibility, the leaf springs can be made shorter for a particular vibratory frequency. Moreover, stresses in the end mountings for the leaf springs are lessened, thus lengthening operating life and reducing maintenance.

Moreover, I have found that by connecting the ends of each leaf spring stack to separate adaptor blocks, which are in turn connected ultimately to the feeder bowl and base at points on a common center line, the angle of inclination of each leaf spring stack may be readily adjusted about this common center line.

The invention accordingly comprises the features of construction, combinations of elements, and arrangement of parts which will be exemplified in the constructions hereinafter set forth, and the scope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view of a vibratory feeder employing one embodiment of the spring system of my invention;

FIGURE 2 is a side elevational view of the spring system of FIGURE 1 showing in detail the individual spring mounting units;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 2;

FIGURE 4 is a side elevational view partially broken away of an alternative embodiment of my invention;

FIGURE 5 is a view taken along line 5-5 of FIG- URE 4; and

FIGURE 6 is modification of the spring mounting unit of FIGURES 4 and 5, constituting the preferred embodiment of my invention.

Similar reference numerals refer to corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION Referring now to FIGURE 1, the vibratory parts feeder, generally indicated at 10, includes a feeder bowl 12 supported on a more massive base 14 by individual spring mounting units, generally indicated at 16. Four spring mounting units 16 are illustrated (FIGURE 3), but three, four or more may be employed. While other forms of vibratory motors are contemplated, an electromagnetic motor is indicated at 18 and includes a field core 20 surrounded by coil winding 22; the core being fixedly mounted to the top of base 14 centrally beneath the feeder bowl 12. The armature (not shown) of the electromagnetic motor 18 is secured to the bottom of the feeder bowl 12 spaced slightly above the field core 20 by an air gap (not shown). Pulsating current energization of the coil winding produces vibratory movement of the feeder bowl 12 with the result that objects therein move up an inclined ramp 24 and feed from ramp termination 26 oneby-one.

As seen in FIGURES 1 through 3, each spring mounting unit 16 consists of a plurality of leaf springs 30 stacked together and inclined at a suitable angle. The leaf springs in each stack are interleaved with spacers (not shown). The lower ends of the stacked leaf springs 30 in each unit 16 are secured to a spring block 32 by a bolt 34. The spring blocks 32 are welded or otherwise affixed to the base 14. The upper ends of the stacked leaf springs 30 in each unit 16 are secured to a spring block 36 by a bolt 37. Each spring block 36 is rigidly attached to the lower corner portion of respective generally triangular spring plates 38 by bolts 40. Each spring plate 38 is, in turn, secured at its upper portion by bolts 42 to a different fiat edge 44 of a rectangular mounting plate 46. The mounting plate 46 is affixed to the bottom of feeder bowl 12.

It is seen that upon energization of the electromagnetic motor 18, the feeder bowl 12 is pulled downwardly and, by virtue of the angular orientation of the leaf springs 30 the relative positioning of spring mounting units 16, rotated about its vertical axis through a small angle in the clockwise direction (FIGURES 1 and 3). On termination of each current pulse through the coil winding 22, the feeder bowl returns to its normal position. Without the spring plates 38, the rotational movement of the feeder bowl would tend to twist the leaf springs 30 about their longitudinal axes, detracting from their flexibility and stressing bolts 34 and 38. The spring plates 38 flex to accommodate the twisting movement on leaf springs 30 resulting from this rotational motion, the leaf springs flexing normal to their longitudinal axes without twist. I have found that the increment of rotational movement of the feeder bowl is increased two to three times when using spring plates 38.

In the embodiment of FIGURES 4 and 5, the ends of the stacked leaf springs 30 in each spring mounting unit 16 are secured by bolts 50 to L-shaped adaptor blocks 52 and 54. The adaptor blocks have leg portions 52' and 54', respectively, lying parallel to the leaf springs 30 and extending toward and beyond each other. Leg por tion 54' is secured adjacent its free end to the upper end portion of an upright rigid plate 56 by a bolt 58. Plate 56 is joined at its lower end to base 14. A bolt 60 secures the lower corner of spring plate 38 to leg portion 52 adjacent its free end. A spacer 62 separates adaptor block 52 from spring plate 38 to avoid interference when the latter flexes to accommodate the incremental rotational movement of the feeder bowl. Similarly spacers 63 separate the leaf spring stack from the adaptor blocks.

As an important feature of my invention, bolts 58 and 60 are located on a common centerline 64. This permits ready adjustment, upon loosening bolts 58 and 60, of the angular orientation of the leaf springs 30 even though they are effectively connected at their ends between spring plate 38 and base 14. Thus, the angle 66 (FIGURE 4) between the leaf springs 30 and vertical can be adjusted with ease to suit the different requirements of different parts to be fed. It is to be noted that this adjustment does not also require a readjustment of the air gap in electromagnetic motor 18. Moreover, the leaf springs can be readily revolved past vertical about centerline 64 to incline in the opposite direction, thereby accommodating a feeder bowl of the opposite hand (parts feed up ramp 24 inclined in opposite direction from that shown in FIG- URE 1). This adjustability is not found in the embodiment of FIGURE 1 as Well as most prior art vibratory feeders of this type.

Moreover, it will be appreciated from FIGURE 4 that the leaf springs 30 may be mounted on either side, but preferably both sides, of the adaptor blocks 52, 54 as shown in FIGURE 6. It is further contemplated that the spring plates 38 may be connected between the lower ends of the leaf springs 30 and the base 14. Additionally, it is seen that the adjustability feature afforded by the adaptor blocks 52 and 54 may be incorporated in linear or in-line vibratory parts feeders which do not require spring plates 38.

It will thus be seen that the objects set forth above, among those made apparent from the preceding descrip. tion, are efficiently attained and, since certain changes may be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention, which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a vibratory parts feeder including a vibrating element, a base and a motor secured to the base in position to impart vibratory motion to the element, a spring system supporting the element on the base, comprising:

(A) a plurality of leaf springs symmetrically arrayed about and beneath the element, each said leaf spring (I) lying in a plane inclined from vertical,

(2) adapted for flexure in a vertical plane, and

(3) rigidly secured at its lower end to said base;

and

(B) separate spring means (1) fixedly connected at one end to the upper end of each said leaf spring, and

(2) fixedly connected at its other end to the element,

(3) lying in a plane substantially perpendicular to the plane of its connected leaf spring, and

(4) adapted to relieve its connected leaf spring of torsional forces resulting from vibratory movement of. the element.

2. The spring system defined in claim 1 wherein:

(1) said spring means are in the form of separate, generally triangularly-shaped spring plates,

(a) each said spring plate being in inverted orientation with its base fixedly connected to the ele ment and its apex fixedly connected to the upper end of one of said leaf springs.

3. The spring system defined in claim 1 which further includes:

(C) a first adaptor interconnecting each said spring means and said upper end of each said leaf spring;

(D) a second adaptor interconnecting said lower end of each said leaf spring to the base,

(1) the point of connection of said first adaptor to said spring means and the point of connection of said second adaptor to the base lying on a common center line about which the angle of inclination of each said leaf spring is readily adjustable.

4. The spring system defined in claim 3 wherein:

(1) each said first adaptor is L-shaped with a first leg fixedly connected to said upper end of each said leaf spring and a generally downwardly extending second leg fixedly connected at a first point adjacent its free end to each said spring means, and

(2) each said second adaptor is L-shaped with a first leg fixedly connected to said lower end of each said leaf spring and a generally upwardly extending second leg fixedly connected at a second point adjacent its free end to the base,

(a) said first and second points lying on a common center line about which the angle of inclination of each said leaf spring is readily adjustable.

5. A vibratory parts feeder comprising, in combination:

(A) a vibrating element;

(B) a base;

(C) a motor mounted between the base and said element in a position impart vibratory motion said element; and

(D) a spring system having at least one spring unit consisting of (1) a leaf spring and a spring member effectively connected end to end between said base and said element in supporting said element on said base,

(a) said leaf spring lying in a plane inclined from vertical for flexure in a vertical plane, (b) said spring means lying in a plane normal to the plane of said leaf spring (i) whereby to relieve said leaf spring of torsional forces resulting from vibratory movement of said element.

6. The vibratory parts feeder refined in claim 5 where- (1) said motor is mounted on said base centrally beneath said element.

7. The vibratory parts feeder defined in claim 5 where- (1) said spring member is in the form of a generally triangularly-shaped spring plate (a) the apex thereof being fixedly connected to one end of said leaf spring.

8. The vibratory parts feeder defined in claim 5 wherein said spring unit further consists of:

(1) first and second adaptors effectively connecting the ends of said leaf spring to said element and said base at points lying on a common center line about which the angle of inclination of said leaf spring is adjustable.

9. The vibratory parts feeder defined in claim 8 wherein said spring unit further consists of (l) at least two parallel leaf springs attached at their ends to said first and second adaptor blocks and arranged on both sides thereof.

10. The vibratory parts feeder defined in claim 8 wherein:

(1) said first adaptor is L-shaped with a first leg fixedly connected to the upper end of said leaf spring and a generally downwardly extending second leg fixedly connected at a first point adjacent its free end ultimately to said element, and

(2) said second adaptor is L-shaped with a first leg fixedly connected to the lower end of said leaf spring and a generally upwardly extending second leg fixedly connected at a second point adjacent its free end ultimately to said base,

(a) said first and second points lying on a common center line about which the angle of inclination of said leaf spring is adjustable.

11. The vibratory parts feeder defined in claim 10 wherein there are:

6 (l) a plurality of said spring units each including a plurality of said leaf springs stacked together. 12. A spring system for vibratory parts feeders having a vibrating element, a base, and a motor positioned on the base to impart vibratory motion to the element, said spring system supporting the element on the base and comprising, in combination:

(A) at least one leaf spring lying in a plane inclined from vertical; (B) a first adaptor block fixedly attached to the upper end of said leaf spring and (1) having a portion extending generally downward in spaced relation to said leaf spring;

(C) a second adaptor block fixedly attached to the lower end of said leaf spring and (1) having a portion extending generally upward in spaced relation to said leaf spring,

(a) said first and second adaptor block portions being relatively off-set and having aligned free end portions;

(D) first means connecting said first adaptor block free end portion to the element at a first point; and

(E) second means connecting said second adaptor block free end portion to the base at a second point,

(1) said first and second points lying on a common center line about which the angle of inclination of said leaf spring is adjustable.

.13. The spring system defined in claim 12 wherein:

(1) said first and second adaptor blocks are L-shaped rigid members physically oriented in complimentary relation.

14. The spring system defined in claim 13 wherein there are:

(l) at least two parallel leaf springs attached at their ends to said first and second adaptor blocks, and arranged on both sides thereof.

References Cited UNITED STATES PATENTS 3,133,627 5/1964 Lenders 198-220 EDWARD A. SROKA, Primary Examiner US. Cl. X.'R. 267-1 

